Optical fiber communication sensing integrated architecture and working method thereof

Abstract

The invention relates to an optical fiber communication sensing integrated architecture and a working method thereof. Comprising a sensing system laser, a coupler, a polarization beam splitter, a semiconductor optical amplifier, a polarization multiplexing communication transmitting system, a polarization wavelength two-dimensional demultiplexer, namely a WDM-PM device, a coarse wavelength division multiplexer MMI-WDM, a single-mode fiber, a polarization multiplexing communication receiving system, a polarization diversity double-balanced photoelectric detector PBPD, and an ROTDR and phi OTDR data processing unit. According to the invention, not only can high-capacity and long-distance communication under fusion of polarization multiplexing and wavelength division multiplexing be realized, but also sensing and communication can be fused through a wavelength division multiplexing system, the quality of sensing signals is improved through polarization diversity reception on the basis, and mutual promotion of communication and sensing is realized.

Description

Technical Field

[0001] The present invention relates to an optical fiber communication perception integrated architecture and a working method thereof, and belongs to the technical field of optical fiber communication. Background Art

[0002] With the large-scale commercial use of the fifth generation of mobile communication (5G) technology, the digital transformation of the economy and society is gradually moving towards multiple scenarios. The low-latency, high-reliability optical fiber network not only effectively improves the user's bandwidth experience, but the sensitive characteristics of the optical fiber itself to perceive external physical parameters also open up a way for the effective implementation of new applications such as pipeline monitoring, urban underground structure digitization, and optical fiber health monitoring. Researchers have proposed that in the 6G era, not only the intelligence level of the network should be further improved, but also the perception ability of the network should be enhanced. The integrated communication and perception (ICAS) of optical networks is an effective design based on optical cable resources, which is in line with the development trend of communication system resource integration. The use of ICAS technology not only helps the intelligent operation and maintenance of optical networks and improves network quality, but also realizes intensive sensor data collection and new applications, effectively revitalizing the optical fiber assets of operators.

[0003] Fiber optic sensing technology appeared almost at the same time as the invention of optical fiber. Using the sensitive characteristics of optical fiber itself in sensing external physical parameters, people have developed a series of fiber optic sensor devices based on backscattered light.

[0004] Rayleigh scattering is an optical phenomenon that occurs when light interacts with tiny particles or molecules. In Rayleigh scattering, the wavelength of light is much larger than the size of the tiny particles or molecules, and the particles or molecules are isotropically distributed. Rayleigh scattering also plays an important role in fiber optic communications. When a light signal propagates in an optical fiber, Rayleigh scattering occurs when it interacts with tiny particles such as inhomogeneities, impurities, and microstructures in the fiber. This scattering causes the attenuation and diffusion of the light signal, affecting the transmission quality and distance of fiber optic communications. Conversely, we can measure the backscattering of the optical fiber to perceive the state of the optical fiber.

[0005] Phase-sensitive optical time-domain reflectometer φOTDR is a distributed optical sensing system based on the principle of backward Rayleigh scattering. It can be divided into two types. In the direct detection system, the continuous light emitted by the light source is modulated into a detection light pulse by an acousto-optic modulator (AOM). The pulse is amplified by an erbium-doped optical fiber amplifier (EDFA) and enters the sensing fiber. The generated back-Rayleigh scattered light is received by a photodetector (PD) after passing through a circulator, and then collected and stored by a data acquisition card (DAQ). Only the intensity change of the signal on the optical fiber can be collected. In the coherent detection system, a balanced photodetector (BPD) replaces the PD, which can collect both the intensity change and the phase change. When external disturbances or temperature changes act on the sensing fiber, the parameters such as the length and refractive index of the optical fiber change, and the optical path and phase of the back-Rayleigh scattered light change accordingly. By detecting and analyzing the intensity or phase change of the reflected light, the disturbance can be detected and identified.

[0006] The working principle of the direct detection φ-OTDR system is described as follows. The signal light field can be expressed as:

[0007]

[0008] Among them, A s is the amplitude of the signal light field, is the phase of the signal light field, and the directly detected light field intensity is:

[0009]

[0010] Different from the direct detection system, in the coherent detection system, the balanced photodetector also receives the frequency f l The light field formula of the local oscillator light is:

[0011]

[0012] Among them, A l is the amplitude of the local oscillator light, is the phase of the local oscillator light, and the light intensity detected on the photodetector after the two beams are mixed and coherent is:

[0013]

[0014] After balanced detection and filtering out the DC term, the final The output current is:

[0015]

[0016] The time delay of the pulse light returning to the detector at the transmitting end after being transmitted through the optical fiber and Rayleigh scattering is τ.

[0017]

[0018] Where L is the length of the pulse light propagating in the optical fiber, v g is the group refractive index of the pulse light in the optical fiber. Therefore, the optical fiber disturbance can be located according to the change of the light intensity I(t) and the time delay τ.

[0019] Spontaneous Raman scattering (RS) is an optical phenomenon in which light and medium are inelastically scattered. The vibration of quartz crystal atoms in optical fiber will produce a lattice wave with a frequency of v. Each of its energies is hv, which is called a phonon. When this phonon participates in the scattering of light, it will cause the wavelength of the scattered light to shift in frequency, which is divided into the Stokes process of down-shifting and the anti-Stokes process of up-shifting. The effect of temperature on thermal vibration in optical fiber will eventually be reflected in the different intensities of Stokes light and anti-Stokes light. This technology can realize the distributed sensing of optical fiber temperature by ROTDR.

[0020] The ROTDR sensing system uses pulsed light to enter the optical fiber and produce Stokes and anti-Stokes backscattered light by inelastic collision with the medium molecules in the optical fiber. Then the temperature point on the optical fiber is located by the principle of optical time domain reflection. The Raman scattered light intensity generated along the optical fiber can be expressed as:

[0021] Anti-Stokes scattered light intensity I as (T,L):

[0022]

[0023] Stokes Intensity I s (T,L):

[0024]

[0025] Where P is the incident light power, K as , K s They represent the coefficients of the Raman anti-Stokes and Stokes backscattering cross sections, S is the backscattering factor, φ ％ Indicates the pulse light flux entering the optical fiber, α4, α as , α sare the attenuation coefficients of the incident light, anti-Stokes scattered light, and Stokes scattered light on the sensing fiber, respectively, and L represents the position of the sensing fiber. h is Planck's constant, Δv is the frequency shift caused by Raman scattering, and k is the Boltzmann constant. It can be seen from the above formula that the intensity of Raman scattered light is related to the temperature T at the position of the optical fiber L. Therefore, the actual temperature along the optical fiber can be demodulated by the above formula. There are currently two commonly used temperature demodulation methods: dual-path and single-path. The main difference between the two methods is that the dual-path demodulation method uses anti-Stokes and Stokes scattered light for temperature demodulation, while the single-path demodulation method only uses anti-Stokes scattered light for temperature demodulation.

[0026] The single-channel demodulation method is similar to the dual-channel demodulation method and is divided into two stages: calibration and measurement. In the calibration stage, the sensing fiber is placed in an environment with a temperature of T4 and a constant temperature, and the Raman anti-Stokes scattered light intensity I is obtained at this time. as (T4,L), obtain the Raman anti-Stokes scattered light intensity I during the measurement phase as (T,L). Comparing the anti-Stokes scattered light intensity in the calibration phase with that in the measurement phase, the final demodulation formula of the single-channel demodulation method is:

[0027]

[0028] The gain mechanism of stimulated Raman light amplification is stimulated Raman scattering (SRS), where energy is transferred from one wavelength to a longer wavelength through a nonlinear scattering process. When a weak signal is launched into an optical fiber with a strong pump, the signal is amplified due to the Raman interaction between the pump and the signal, forming stimulated Raman scattering.

[0029] Wavelength division multiplexing (WDM) technology allows multiple independent wavelength bands to be transmitted on one optical fiber, thus providing multiple channels and higher communication capacity, making the communication capacity grow exponentially with the number of multiplexed wavelengths. In optical fiber communication, the wavelength division multiplexing system is undergoing a transformation from point-to-point system to transparent optical network, and from the previous electro-optical conversion to all-optical switching. Dense wavelength division multiplexing (DWDM) has become the preferred technology for optical fiber communication today, especially in long-distance and backbone networks. Arrayed Waveguide Grating (AWG), as the core device for building ultra-large capacity wavelength division multiplexing systems, has the advantages of small wavelength spacing, multiple channels, flat output spectrum, and easy integration, and is widely used in WDM optical networks.

[0030] The biggest advantage of coherent optical amplification technology and coherent detection system is that it can improve the spectrum efficiency and detection sensitivity of the receiver of the optical fiber communication system. The basic principle of coherent optical communication is as follows: Figure 1 As shown, at the signal transmitting end, the signal to be transmitted is modulated onto an optical carrier by an optical modulator through external modulation. After being transmitted in the optical fiber, it reaches the signal receiving end. The receiving end sends the signal to the optical mixer for coherent mixing with the local oscillator light generated by the local oscillator laser. The photocurrent output by the photodetector is processed and output in the form of a baseband signal. Since the intermediate frequency signal power component of the optical signal output after mixing can carry the amplitude, frequency and phase information of the signal light, it can be reflected in the intermediate frequency signal regardless of the modulation method used by the transmitting end. Therefore, the coherent optical communication method is applicable to all modulation methods and can obtain all information of the signal including amplitude, frequency and phase. (Recent related technical achievements: Tang Ming, Li Weihao, Zhang Mingming, et al. Coherent source homodyne coherent optical transmission technology [J]. Chinese Laser, 2022, 49(12): 223-237.)

[0031] Polarization diversity reception; The phase-sensitive optical time-domain reflectometer (Φ-OTDR) system has made significant progress in the measurement of dynamic characteristics of optical fibers since it was proposed by Taylor et al. in 1993 due to its high sensitivity and fast response speed. However, the fading noise existing in the Φ-OTDR system is a key issue that affects the improvement of its signal-to-noise ratio. Fading noise includes interference fading and polarization fading, which will lead to the deterioration of the demodulation results of the Φ-OTDR system, the reduction of the signal-to-noise ratio (SNR), and the distortion of the demodulation results. With the continuous in-depth research on the Φ-OTDR system, various anti-fading noise technologies have been proposed. In order to eliminate the influence of fading in the system, the most commonly used method is to superimpose multiple groups of independently measured signals, among which polarization diversity reception. Is it like Figure 3 As shown, two polarization beam splitters (PBS) are used to decompose the signal light and the intrinsic light into two groups of light beams with orthogonal polarization states. The light of the same polarization state is coupled and received by a balanced photodetector (BPD). According to the Jones matrix, the electric field vectors of the signal light and the intrinsic light can be expressed as:

[0032]

[0033] In the formula, ω s , θ s and ε s are the angular frequency, phase, azimuth and ellipticity of the signal light, θ l , θ l and ε l are the angular frequency, phase, azimuth and ellipticity of the local oscillator light. After passing through the polarizer with an angle of θ with the x-axis, the output intensity of the interference signal can be expressed as:

[0034]

[0035] in, is the phase difference between the intrinsic light and the signal, Δω is the angular frequency difference between the local oscillator light and the signal light, Δω=ω s -ω l When it is assumed that both the intrinsic light and the signal light are linearly polarized, ε s =ε l = 0. Since the dual-state polarization diversity reception uses orthogonal polarization states, The value of k is 0 or 1, so the interference signal received by the receiving end can be expressed as:

[0036]

[0037] It can be seen from formula (4) that the amplitudes of the two signals are not the same, so the fading noise can be suppressed by combining the two signals.

[0038] Polarization multiplexing technology; The demand for communication capacity in optical fiber communication systems has made polarization division multiplexing technology common. Polarization division multiplexing technology utilizes the basic polarization principle of light, which can directly double the spectrum efficiency. Light is an electromagnetic wave, and its vibration direction is perpendicular to the direction of light propagation. Its vibration mode is the polarization state of light. Light can generally be divided into natural light, partially polarized light, and fully polarized light. The optical carrier emitted in the optical fiber communication system is fully polarized light. Light can be decomposed into two polarized lights with orthogonal polarization directions, and they are independent of each other, so information can be loaded separately on the two orthogonal polarizations. (Recent related technical achievements: Lu Qingmin. Demultiplexing method of high-order modulated signals of polarization multiplexing in the electrical domain and optical domain [D]. Beijing University of Posts and Telecommunications, 2023. DOI: 10.26969 / d.cnki.gbydu.2023.001589.)

[0039] Semiconductor optical amplifier (SOA) technology, semiconductor optical amplifier is a device that uses semiconductor lasers as amplifiers. Its notable feature is that it can directly convert light / light without going through the process of light-to-electricity conversion and electricity-to-light conversion, and it has a large gain bandwidth. In addition, its operating band can cover the 1.3-1.6μm band. The principles and characteristics of semiconductor optical amplifiers are similar to those of semiconductor lasers, both of which are based on the mechanism of stimulated emission of light. The active region structure composed of a double heterostructure uses the current injection method to inject electrons and holes, and realizes light amplification through the transition from the excited energy level conduction band with high electron energy to the low energy level valence band. It is a particle number inversion amplification luminescence, and the medium of luminescence is non-equilibrium carriers, namely electron-hole pairs.

[0040] When a forward current is injected into a semiconductor optical amplifier and reaches a certain value, the number of free electrons in the N region increases and continuously enters the PN junction to recombine with holes, releasing energy in the form of photons. The photons are induced by the input optical signal to form stimulated radiation, so that the released photons are at the same frequency, direction, phase, and polarization direction as the incident photons, and continue to be induced to generate stimulated radiation as the photons continue to move forward, thereby generating more new photons, amplifying the input optical signal. When the semiconductor laser is not injected with a forward current, the light injected into the SOA will be absorbed by the PN junction, thereby generating electron-hole pairs, and the macroscopic manifestation at this time is that the incident light is absorbed. Therefore, for the characteristics of SOA that it will amplify light when powered on and absorb light when not powered on, SOA can be used as a modulator.

[0041] The pulse extinction ratio is one of the parameters to measure the quality of the modulated pulse. It refers to the ratio of the average power of the pulse light output "1" to "0", and the unit is dB. SOA is mainly composed of a passive layer (Passive layer) and an active layer (Active layer): when the injected pump current is greater than the threshold current, the carriers in the active layer undergo stimulated radiation and generate photons identical to the incident light, thereby amplifying the incident light; when there is no pump current or the injected pump current is less than the threshold current, the incident light is absorbed. As a modulator, the extinction ratio of SOA can reach more than 40dB. At the same time, its low price and easy laser integration make it a natural advantage as a modulator.

[0042] Based on the above optical network communication and sensing technologies: optical time domain reflectometry (OTDR), phase-sensitive optical time domain reflectometry (φOTDR), Brillouin optical time domain reflectometry (BOTDR), Raman optical time domain reflectometry (ROTDR), etc., distributed sensing of transmission loss, vibration, temperature and other information in optical fibers can be achieved. Currently, there are product-level devices on the market for these technologies, including optical time domain reflectometers (OTDR) that can measure optical fiber length, optical fiber transmission attenuation, joint attenuation and fault location, DVS systems that use φOTDR technology to perform distributed monitoring of optical fiber vibration, and DTS systems that use ROTDR technology to perform distributed monitoring of optical fiber temperature.

[0043] Although the above products can be applied to existing optical fiber communications without affecting the communication channels, and basic communication perception can be realized simultaneously in one optical fiber, these technologies and equipment are all for detecting a certain parameter of the optical fiber, and it is impossible to achieve simultaneous measurement of multiple parameters and collect single information under the premise of sharing hardware equipment.

[0044] In addition, these devices are only designed for fiber-optic distributed detection and do not take into account the design of an integrated architecture for fiber-optic communication perception. They are difficult to fully integrate into the communication network to achieve an integrated architecture for communication-enhanced perception and perception-assisted communication. Summary of the invention

[0045] In view of the difficulty in integrating optical fiber multi-parameter sensing and communication, the present invention proposes a new communication and perception integrated architecture. This architecture can not only integrate communication and perception to achieve multi-parameter perception, but also promote the mutual promotion of perception and communication.

[0046] The present invention also proposes a working method of the optical fiber communication perception integrated architecture.

[0047] The technical solution of the present invention is:

[0048] An integrated optical fiber communication sensing architecture, comprising:

[0049] Sensing system laser, coupler, polarization beam splitter, semiconductor optical amplifier, polarization multiplexing communication transmission system, polarization wavelength dual-dimensional demultiplexer based on full-row waveguide grating, namely WDM-PM device, coarse wavelength division multiplexer MMI-WDM, single-mode optical fiber, polarization multiplexing communication receiving system, polarization diversity dual-balanced photodetector PBPD, ROTDR and φOTDR data processing unit;

[0050] At the transmitting end of the optical fiber communication system, the sensing light signal is emitted by the sensing system laser as a narrow-linewidth laser, and then split by a 1:9 coupler. 10% of the light is used as local oscillator light to achieve coherent amplification of the backscattered Rayleigh light, and 90% of the light is used as signal light to undergo single-pulse modulation by a semiconductor optical amplifier (SOA).

[0051] The modulated single pulse sensing optical signal is then split into two orthogonal polarization pulse lights by a polarization beam splitter (PBS). These two orthogonal polarization pulse lights enter the WDM-PM device together with other C-band polarization multiplexed optical signals to achieve multi-dimensional multiplexing of polarization and wavelength.

[0052] The multiplexed optical signal becomes two beams of multi-wavelength multiplexed light with orthogonal polarization states. These two beams of multi-wavelength multiplexed light each pass through a coarse wavelength division multiplexer MMI-WDM again to achieve demultiplexing of the C-band light and the 1550nm spontaneous Raman scattered anti-Stokes light 1450nm wavelength light; then the two beams of multi-wavelength multiplexed light are coupled through a polarization beam splitter (PBS) to become a beam of WDM-PM light, and then enter the single-mode optical fiber for propagation.

[0053] The WDM-PM light carrying the signal propagates forward, and the sensing optical signal returns to the transmitter. After polarization diversity reception, it enters the sensing system for data processing, thereby locating the continuity, loss, temperature, stress and vibration information of the optical fiber.

[0054] Preferably, according to the present invention, the fiber optic communication sensing integrated architecture further includes a Raman amplifier, which uses the entire optical fiber as a gain medium to achieve gradual amplification of light in a long-distance optical fiber.

[0055] Preferably according to the present invention, the optical fiber communication system is a C-band wavelength division multiplexing system.

[0056] Further preferably, the wavelength of the Raman pump laser is selected as the wavelength of the anti-Stokes light of the sensing light signal.

[0057] Further preferably, the introduction of the Raman amplifier amplifies four types of light, including:

[0058] The forward transmitted WDM-PM optical signal is the WDM-PM light that carries the signal;

[0059] A single pulse of light for sensing in the forward direction;

[0060] Backscattered Rayleigh light used in sensing to locate loss, continuity, stress, and vibration;

[0061] Backscattered Rayleigh light used to locate on / off and temperature in sensing;

[0062] After Raman amplification of the forward transmitted optical signal, it passes through the combination of polarization beam splitter and WDM-PM device to realize wavelength division multiplexing and polarization demultiplexing. The polarized light carrying different signals is received by the polarization multiplexing communication receiving system.

[0063] The back-scattered Rayleigh light is returned along the original transmission fiber through Raman. During the return process, the back-scattered Rayleigh light is amplified by the Raman pump laser, and the back-scattered anti-Stokes light is superimposed with the Raman pump light to increase the basic optical power, making it easier for the detector to receive.

[0064] After backscattering, the sensing optical signal containing the fiber connection, loss, stress, vibration, and temperature returns to the transmitting end and is firstly divided into two optical signals with orthogonal polarizations by a polarization beam splitter. The two optical signals with orthogonal polarizations are respectively passed through a coarse wavelength division multiplexer MMI-WDM to realize the demultiplexing of the C-band backscattered Rayleigh light and the anti-Stokes light of the backscattered Raman of the sensing light.

[0065] After demultiplexing, the anti-Stokes light of Raman backscattering with orthogonal polarization states is received by polarization diversity and processed as ROTDR signal. By processing the light intensity information and comparing it with the pulse emission time, the temperature information of the entire optical fiber is demodulated and located.

[0066] After demultiplexing, the back-Rayleigh scattered light of the C band with orthogonal polarization states is demultiplexed in wavelength and polarization state through the WDM-PM device. The back-Rayleigh scattered light with orthogonal polarization states of the single pulse light generated by the optical transmitter of the sensing system is coherent with the two polarization orthogonal local oscillator lights of the transmitting end after passing through the circulator and is received by the polarization diversity dual-balanced photodetector PBPD.

[0067] Preferably, according to the present invention, the polarization diversity dual balanced photodetector PBPD includes a polarization beam splitter PBS and a balanced photodetector BPD; the polarization beam splitter PBS divides the input local oscillator light and signal light into two orthogonal polarization states, and the two signal lights of different polarization states are respectively coherent with the local oscillator light and received by the two balanced photodetectors BPD, thereby realizing the coherent reception of two orthogonal polarization state signals; the signal detected by the PBPD is collected by the acquisition card and then data processed, i.e., the loss, continuity, stress, vibration and other information of the demodulated and located optical fiber is processed.

[0068] The working method of the above-mentioned optical fiber communication perception integrated architecture includes:

[0069] At the transmitting end of the optical fiber communication system, the sensing light signal is emitted by the sensing system laser as a narrow linewidth laser, and then modulated into a single pulse by a semiconductor optical amplifier;

[0070] The modulated single pulse sensing optical signal is then split into two orthogonal polarization pulses by a polarization beam splitter. These two orthogonal polarization pulses enter the WDM-PM device together with other C-band polarization multiplexed optical signals to achieve multi-dimensional multiplexing of polarization and wavelength.

[0071] The multiplexed optical signal becomes two beams of multi-wavelength multiplexed light with orthogonal polarization states. The two beams of multi-wavelength multiplexed light each pass through a full-band wavelength division multiplexer again to achieve demultiplexing of C-band light and 1550nm spontaneous Raman scattered anti-Stokes light 1450nm wavelength light; then the two beams of multi-wavelength multiplexed light are coupled through a polarization beam splitter PBS to become a beam of WDM-PM light, which then enters the optical fiber for propagation;

[0072] The WDM-PM light carrying the signal propagates forward, and the sensing optical signal returns to the transmitting end, and enters the ROTDR and φOTDR data processing units for data processing after polarization diversity reception, thereby locating the continuity, loss, temperature, stress and vibration information of the optical fiber.

[0073] The beneficial effects of the present invention are:

[0074] 1. The communication signal and the sensor signal are integrated into the same optical fiber for transmission through a multi-dimensional multiplexing system of wavelength division multiplexing and polarization multiplexing. On the premise that the communication and sensor signals do not affect each other, a laser with the same wavelength as the anti-Stokes light of the sensor light source is introduced as the pump light of the Raman fiber amplifier. This can not only realize high-capacity and long-distance communication under the fusion of polarization multiplexing and wavelength division multiplexing, but also integrate sensing and communication through the wavelength division multiplexing system, and on this basis, improve the quality of the sensor signal through polarization diversity reception, so as to achieve mutual promotion of communication and sensing.

[0075] 2. Multi-parameter sensing: Currently available fiber optic sensing technologies that do not affect communication services include OTDR, φOTDR, ROTDR, BOTDR, etc. OTDR uses wide-spectrum light and can only sense the loss and continuity of the optical fiber, but cannot sense the stress, vibration, and temperature of the optical fiber; φOTDR uses a narrow-linewidth light source to directly detect the self-coherence of the back-scattered Rayleigh light, which can sense the continuity and vibration of the optical fiber, but cannot measure temperature; ROTDR can achieve distributed temperature sensing by detecting and comparing the anti-Stokes light and Stokes light of the sensing light source, but cannot identify the stress and vibration of the optical fiber. The present invention combines φOTDR with ROTDR, uses the same laser as the detection light source, and processes four parallel data signals at the receiving end through a data acquisition card to achieve multi-parameter sensing of optical fiber continuity, stress, vibration, and temperature. At the same time, the sharing of hardware equipment in the sensing system greatly reduces costs.

[0076] 3. Mutual promotion of sensing and communication: At present, most of the integrated sensing equipment and technologies are still at the stage where communication and sensing do not affect each other, and there is no mutual promotion. However, the introduction of Raman fiber amplifiers not only solves the problem of weak back Rayleigh scattered light and Raman scattered light of traditional φOTDR and ROTDR, and short detection distance, but also effectively utilizes the advantage of the gain spectrum width of Raman fiber amplifiers to achieve optical amplification of the communication signal band while amplifying the sensing signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 Schematic diagram of the basic principle of coherent optical communication:

[0078] Figure 2 It is a structural schematic diagram of the integrated optical fiber communication and sensing architecture of the present invention;

[0079] Figure 3 It is a schematic diagram of the structure of the polarization diversity double-balanced photoelectric detector PBPD of the present invention;

[0080] Figure 4 Schematic diagram of the input effect of introducing Raman amplification;

[0081] Figure 5 Schematic diagram of the output effect of introducing Raman amplification;

[0082] Figure 6 This is a schematic diagram of the relationship between the peak power of the pulse at the receiving end and the length of the Raman amplification fiber;

[0083] Figure 7 It is a schematic diagram of the phase comparison between traditional reception and polarization diversity reception;

[0084] Figure 8 This is a schematic diagram of traditional OTDR results;

[0085] Fig. 9 yes Figure 8 A magnified detail diagram at 300 meters;

[0086] Fig.10 yes Figure 8 A magnified detail diagram at 1700 meters;

[0087] Fig.11 It is a time domain diagram of the optical pulse at the transmitter end of the sensing system;

[0088] Fig.12 This is a schematic diagram of the receiving result without Raman laser superposition and amplification;

[0089] Fig.13 This is a schematic diagram of the receiving result after Raman laser superposition and amplification; DETAILED DESCRIPTION

[0090] The present invention will be further defined below in conjunction with the accompanying drawings and embodiments, but is not limited thereto.

[0091] Example 1

[0092] An integrated optical fiber communication sensing architecture, comprising:

[0093] Sensing system laser, coupler, polarization beam splitter, semiconductor optical amplifier, polarization multiplexing communication transmission system, polarization wavelength dual-dimensional demultiplexer based on full-row waveguide grating, namely WDM-PM device, coarse wavelength division multiplexer MMI-WDM, single-mode optical fiber, polarization multiplexing communication receiving system, polarization diversity dual-balanced photodetector PBPD, ROTDR and φOTDR data processing unit;

[0094] Connection relationship such as Figure 2As shown, the polarization multiplexing communication transmitting system is connected to the polarization wavelength dual-dimensional demultiplexer based on the whole column waveguide grating, namely the WDM-PM device, as the starting end, and then connected to the coarse wavelength division multiplexer MMI-WDM to realize full-band wavelength division multiplexing, and then connected to the PBS to realize polarization multiplexing. Then it is connected to the optical fiber for transmission. A Raman pump laser is connected to the optical fiber, and Raman amplification is realized with the optical isolator. At the receiving end, the PBS is connected to the tail end of the optical fiber transmission to realize polarization demultiplexing, and then the polarization wavelength dual-dimensional demultiplexer based on the whole column waveguide grating, namely the WDM-PM device, is connected to the polarization multiplexing communication receiving system to realize communication signal reception. In addition, at the transmitting end, another group of MMI-WDM devices are connected to the PBS at the incident end of the optical fiber to realize the demultiplexing of the backscattered signal. Then it is connected to the polarization diversity receiving PBPD to convert the optical signal carrying temperature information into an electrical signal, and then it is connected to the data processing unit to realize data processing and temperature demodulation. At the other end, the circulator is connected to two channels of the polarization wavelength dual-dimensional demultiplexer AWG based on a whole column of waveguide gratings to realize the demultiplexing of the φOTDR signal, and then connected to the polarization diversity receiving system. In addition, the sensor system laser is connected to the 1:9 coupler, and 90% of the light energy is connected to the SOA as the sensor signal for modulation and then connected to the polarization wavelength dual-dimensional demultiplexer AWG based on a whole column of waveguide gratings through the PBS for transmission, while the other end of the coupler 10% of the output passes through the PBS and enters the polarization diversity receiving. The polarization diversity dual-balanced photodetector PBPD realizes coherent balanced detection, and the detected signal is connected to the φOTDR data processing unit for data processing and vibration information demodulation.

[0095] The basic principles of coherent optical communication are as follows: Figure 1 As shown, the fiber optic communication perception integrated architecture design of the present invention is based on the current large-capacity, low-latency, high-bandwidth wavelength division multiplexing-polarization multiplexing (WDM-PM) coherent optical communication system. Under the premise of not affecting the communication system, a multi-parameter distributed sensing system such as on / off, loss, temperature, stress, vibration, etc. is introduced through the wavelength division multiplexing system to realize the integrated design of fiber optic communication perception.

[0096] At the transmitting end of the optical fiber communication system, the sensing optical signal emits a narrow linewidth laser through the sensing system laser, and then splits through a 1:9 coupler, where 10% of the light is used as local oscillator light to achieve coherent amplification of the backscattered Rayleigh light, and 90% of the light is used as signal light to pass through a semiconductor optical amplifier (SOA) for single pulse modulation; since SOA can amplify the optical signal when powered, and has a strong absorption effect on the optical signal when not powered, it can be used as a modulator. The pulse modulation used in the sensing system is single pulse modulation with a low modulation rate, so there is no need to use a high-speed electro-optical modulator to modulate the outgoing signal. Using SOA optical switch as a modulator can not only achieve pulse modulation, but also achieve optical signal amplification. At the same time, SOA has a relatively good integration with semiconductor lasers widely used in optical communication systems, and SOA is relatively cheap, making it an excellent choice as a sensor system modulator.

[0097] The modulated single pulse sensing light signal is then split into two orthogonal polarization pulse lights by a polarization beam splitter (PBS). These two orthogonal polarization pulse lights enter the WDM-PM device together with other C-band polarization multiplexed optical signals to achieve multi-dimensional multiplexing of polarization and wavelength. Here, the sensing light only occupies one wavelength channel of the traditional optical communication system.

[0098] The multiplexed optical signal becomes two beams of multi-wavelength multiplexed light with orthogonal polarization states. The two beams of multi-wavelength multiplexed light are respectively passed through a coarse wavelength division multiplexer MMI-WDM to demultiplex the C-band light and the 1550nm spontaneous Raman scattered anti-Stokes light 1450nm wavelength light. After that, the two beams of multi-wavelength multiplexed light are coupled through a polarization beam splitter (PBS) to become a beam of WDM-PM light, and then enter the single-mode optical fiber for propagation.

[0099] The WDM-PM light carrying the signal propagates forward like the traditional optical communication system, and the sensing light signal returns to the transmitter due to backward Rayleigh scattering and backward Raman scattering, and enters the sensing system for data processing after polarization diversity reception, so as to locate the on-off, loss, temperature, stress and vibration information of the optical fiber. However, after long-distance optical fiber transmission, due to severe light attenuation, especially the intensity of backward Rayleigh scattered light is 30dB lower than the forward transmission light power, and the intensity of Raman scattered light is about 80dB lower than the forward transmission light power, so both signal light and backscattering need to be optically amplified after long-distance transmission to extend the transmission distance.

[0100] Coupler: couples two beams of light into one beam.

[0101] Polarization multiplexing communication transmission system: The transmitting end of the communication system can transmit multi-wavelength and polarization multiplexed optical signals.

[0102] Raman fiber amplifier: light amplification is achieved through the Raman effect.

[0103] Polarization multiplexing communication receiving system: The receiving end of the communication system can realize the reception and processing of dual-dimensional signals of polarization and wavelength.

[0104] ROTDR and φOTDR data processing unit: realizes data processing of signals received by the sensor system and demodulates vibration and temperature information.

[0105] Example 2

[0106] According to the optical fiber communication sensing integrated architecture described in embodiment 1, it is characterized by:

[0107] The communication signals and sensor signals transmitted in the optical fiber will attenuate as the propagation distance increases. In order to extend the optical transmission and sensing distance as much as possible, we use reverse Raman pumping to perform Raman amplification on the signal. Since the gain bandwidth of the Raman amplifier can reach 6THz, it can achieve optical amplification of the entire C-band communication signal and the φOTDR back-Rayleigh scattering sensor signal. In addition, compared with EDFA, the distributed gain method of the Raman amplifier can achieve gradual amplification of the signal and will not generate excessive optical power in a certain section of the optical fiber, thereby avoiding the influence of nonlinearity as much as possible.

[0108] The integrated architecture of optical fiber communication and perception also includes Raman amplifiers. In traditional optical communication and separate distributed optical fiber sensing systems, erbium-doped fiber amplifiers (EDFA) are generally used for optical amplification. However, in the integrated optical communication and perception system, in order to avoid the crosstalk problem caused by multi-wavelength multiplexing, the fiber input power needs to be reduced as much as possible. The fiber input optical power of the general communication system is about 0dBm, while the fiber input power of the sensing system is usually selected to be 15dBm in order to increase the sensing distance, which leads to the incompatibility between communication and sensing. In order to achieve the integration of optical fiber communication and perception, it is necessary to reduce the fiber input power of the sensing optical signal, but this will bring about the problem of reduced sensing distance, so optical amplification needs to be introduced. However, although EDFA optical amplification technology is mature, it will inevitably produce higher peak power to achieve high-gain optical amplification at a shorter distance, which is not conducive to the integrated system of inter-sensing and is easy to produce larger nonlinear effects. In addition, the gain spectrum of EDFA is fixed near 1550nm, and the gain spectrum is narrow. Raman amplifier uses the entire optical fiber as a gain medium to achieve gradual amplification of light in long-distance optical fibers. This not only reduces the peak power of the sensing light and signal light in the optical fiber and reduces the impact of nonlinear effects, but also the Raman amplifier amplifies the long-distance light of the back Rayleigh scattering, which can greatly extend the sensing distance of the φOTDR.

[0109] In addition, ultra-long-distance optical communication and perception integration are achieved by introducing multi-stage Raman amplification.

[0110] The optical fiber communication system is a wavelength division multiplexing system in the C band.

[0111] In addition, the Raman gain spectrum can achieve full-band optical gain by adjusting the wavelength of the pump laser. The wavelength of the Raman pump laser is selected to be the wavelength of the anti-Stokes light of the sensing light signal. In this way, not only can the Raman amplifier be used to achieve wide-spectrum amplification of the signal light, the forward propagating sensing light, and its back-scattered Rayleigh light, but also the basic power of the back Raman scattering of the signal light can be increased by superposition, thereby improving the overall performance of the system.

[0112] The introduction of Raman amplifiers amplifies four types of light, including:

[0113] The forward transmitted WDM-PM optical signal is the WDM-PM light that carries the signal;

[0114] Forward-transmitted single pulse light for sensing; The light source of the single pulse light for sensing comes from the laser of the sensing system. The laser emits continuous light, which is modulated into a single pulse light by the SOA.

[0115] Backscattered Rayleigh light used in sensing to locate loss, continuity, stress, and vibration;

[0116] Backscattered Rayleigh light used to locate on / off and temperature in sensing;

[0117] After Raman amplification of the forward transmitted optical signal, it passes through the combination of polarization beam splitter and WDM-PM device to realize wavelength division multiplexing and polarization demultiplexing. The polarized light carrying different signals is received by the polarization multiplexing communication receiving system.

[0118] The back-scattered Rayleigh light returns along the original transmission optical fiber through Raman. During the return process, the back-scattered Rayleigh light is amplified by the Raman pump laser, and the anti-Stokes light of the back-scattered Raman is superimposed with the Raman pump light to increase the basic optical power, making it easier for the detector to receive; the Gaussian noise of the Raman pump laser can be reduced by the averaging algorithm, thereby demodulating and locating the temperature information.

[0119] After backscattering, the sensing optical signal containing the fiber connection, loss, stress, vibration, and temperature returns to the transmitting end and is firstly divided into two optical signals with orthogonal polarizations by a polarization beam splitter. The two optical signals with orthogonal polarizations are respectively passed through a coarse wavelength division multiplexer MMI-WDM to realize the demultiplexing of the C-band backscattered Rayleigh light and the anti-Stokes light of the backscattered Raman of the sensing light.

[0120] After demultiplexing, the anti-Stokes light of Raman backscattering with orthogonal polarization states is received by polarization diversity and processed as ROTDR signal. By processing the light intensity information and comparing it with the pulse emission time, the temperature information of the entire optical fiber is demodulated and located.

[0121] After demultiplexing, the back-Rayleigh scattered light of the C band with orthogonal polarization states is demultiplexed in wavelength and polarization state through the WDM-PM device. The back-Rayleigh scattered light with orthogonal polarization states of the single pulse light generated by the optical transmitter of the sensing system is coherent with the two polarization orthogonal local oscillator lights of the transmitting end after passing through the circulator and is received by the polarization diversity dual-balanced photodetector PBPD.

[0122] like Figure 3 As shown, the polarization diversity dual balanced photodetector PBPD includes a polarization beam splitter PBS and a balanced photodetector BPD; the polarization beam splitter PBS divides the input local oscillator light and signal light into two orthogonal polarization states, and the two signal lights of different polarization states are respectively coherent with the local oscillator light and received by two balanced photodetectors BPD, realizing the coherent reception of two orthogonal polarization state signals; wherein the coherent reception realizes the amplification of the signal light, and the BPD balanced detection doubles the signal light by removing the DC difference, and at the same time removes the common mode noise in the process of removing the DC component, greatly improving the signal-to-noise ratio, which is conducive to the detection and demodulation of small disturbances. The signal detected by the PBPD is collected by the acquisition card and then processed, that is, the loss, continuity, stress, vibration and other information of the demodulated and located optical fiber are demodulated.

[0123] The integrated optical fiber communication sensing architecture realizes the introduction of φOTDR and ROTDR in the WDM-PM system. Without affecting the communication service signals, it realizes distributed monitoring of the entire optical fiber loss, continuity, stress, vibration, temperature and other information through polarization diversity reception and balanced detection. At the same time, the Raman amplification technology is used to extend the signal transmission and sensing distance.

[0124] The present invention adopts polarization multiplexing-wavelength division multiplexing (PM-WDM) equipment: this not only meets the demand for large-capacity communication under multi-dimensional multiplexing of wavelength division multiplexing and polarization multiplexing in optical fiber communication, but also meets the requirement for polarization diversity reception of sensor signals such as φOTDR and ROTDR under wavelength division multiplexing system.

[0125] The wavelength division multiplexer MMI-WDM based on the principle of multi-mode interference is used. The device can realize large-bandwidth wavelength division multiplexing and demultiplex the anti-Stokes light in the sensing light signal and the signal light band. This has a unique advantage over the free spectrum region (FSR) of devices such as arrayed waveguide gratings (AWG), which is difficult to span different bands.

[0126] A rectangular single pulse with a wavelength of 1550nm and a peak power of 1mW is input into the optical fiber; the pump light wavelength of the Raman amplifier is 1450nm and the pump power is 1W. After 100km of optical fiber transmission, the peak power of the pulsed light detected at the receiving end is higher than 5mW, which can verify the amplification effect of Raman amplification on signal light and sensor light. By scanning the optical fiber length and the average power at the receiving end, it can be seen that under the condition of the existing input and pump source being determined, the optimal amplification distance of Raman amplification is 40km, and the power compensation amplification distance is 95km. Therefore, in order to achieve the maximum received power, a Raman pump laser can be set 40km before the receiving end, and in order to achieve long-distance transmission, the pump laser of the Raman multi-stage amplification is set at an interval of 95km.

[0127] Polarization diversity reception can avoid polarization fading-related losses and improve the signal power stability at the receiving end.

[0128] Figure 4 This is a schematic diagram of the input effect of introducing Raman amplification; the horizontal axis is time and the vertical axis is the power of the light pulse. It can be seen from the figure that before Raman amplification, the output peak power of the rectangular pulse is 1mW. Figure 5 This is a schematic diagram of the output effect of introducing Raman amplification; the horizontal axis is time, and the vertical axis is the power of the optical pulse. It can be seen from the figure that after Raman amplification, although the shape of the rectangular pulse is slightly distorted, the output peak power is greater than 5mW. Figure 4 The 1mW achieves more than 5 times light amplification. Figure 6 It is a schematic diagram of the relationship between the peak pulse power at the receiving end and the length of the Raman amplification fiber; the horizontal axis is the length of the fiber introduced with Raman amplification, and the vertical axis is the signal light power at the receiving end. By scanning the fiber length and the average power at the receiving end, it can be seen that under the condition of the existing input and pump source, the optimal amplification distance of Raman amplification is 40km, and the power compensation amplification distance is 95km. Therefore, in order to achieve the maximum receiving power, the Raman pump laser can be set 40km before the receiving end, and in order to achieve long-distance transmission, the pump laser of the Raman multi-stage amplification is set at an interval of 95km. Figure 7 This is a phase comparison diagram of traditional reception and polarization diversity reception; the horizontal axis is time and the vertical axis is phase. The red line is the traditional direct reception, and the black line is the result after polarization diversity reception. The comparison shows that after polarization diversity reception, the power can be stabilized and the impact of polarization fading can be solved. Figure 8 This is a schematic diagram of traditional OTDR results; the horizontal axis is the length of the optical fiber from the transmitting end, and the vertical axis is the received back Rayleigh scattering intensity. From the figure, it can be seen that there are some pseudo gain and loss event points and the fiber end. Among them, the loss point can be judged as a fiber bending and welding event, and the pseudo gain is a fiber joint event. Fig. 9 yes Figure 8The enlarged detail diagram at 300 meters; it can be seen that the optical fiber has a loss event of about 0.2dB at 300 meters. Based on experience, it can be judged that the optical fiber has a high probability of having a fusion splice at 300 meters. Fig.10 yes Figure 8 A schematic diagram of the enlarged details at 1700 meters; it can be seen that the optical fiber has a pseudo gain of about 4.5dB at 300 meters. Based on experience, it can be judged that there is a fiber optic connector at 1700 meters with a high probability. Fig.11 It is a time domain diagram of the optical pulse at the transmitting end of the sensor system; the horizontal axis is time and the vertical axis is power. Fig.12 This is a schematic diagram of the receiving result without Raman laser superposition and amplification; the horizontal axis is time and the vertical axis is optical power. It can be seen that the rectangular pulse at the transmitting end has been bent and submerged in the noise after being received at the receiving end after Rayleigh scattering. Fig.13 It is a schematic diagram of the receiving result after Raman laser superposition and amplification; the horizontal axis is time and the vertical axis is optical power. It can be seen that after the rectangular pulse at the transmitting end is superimposed and amplified by the Raman laser, the Rayleigh scattered light can be seen as the original pulse different from the noise after being received at the receiving end.

[0129] The static conditions and events of the optical fiber can be located according to the changes in the intensity of the backscattered light signal. The intensity of the Rayleigh scattered light at the event point will change dramatically. The optical fiber fusion loss is manifested as a cliff-like drop in power, generally with a value of about 0.2dB. The joint event will bring about pseudo gain, and a higher Fresnel reflection will appear at the end of the optical fiber. The type of the optical fiber end can be determined by judging the intensity of the Fresnel reflection.

[0130] When the pump light of the Raman amplifier has the same wavelength as the anti-Stokes light of the back Raman scattering, the influence of the dark current can be weakened by superposition amplification. The modulated rectangular pulse is a regular single pulse. After receiving, the rectangular pulse is submerged by the dark current and noise due to the low power. At this time, it can be superimposed and amplified by another beam of light with the same frequency. The basic power of the optical signal can be increased by an additional light beam, thereby avoiding the influence of the dark current submerging the signal, and the Gaussian noise can be eliminated by cumulative averaging.

[0131] Example 3

[0132] The working method of the optical fiber communication perception integrated architecture described in embodiment 1 or 2 includes:

[0133] At the transmitting end of the optical fiber communication system, the sensing light signal is emitted by the sensing system laser as a narrow linewidth laser, and then is modulated into a single pulse by a semiconductor optical amplifier. Using an SOA optical switch as a modulator can not only realize pulse modulation, but also amplify the optical signal. At the same time, SOA has a relatively good integration with semiconductor lasers widely used in optical communication systems, and SOA is relatively inexpensive, making it an excellent choice as a sensing system modulator.

[0134] The modulated single pulse sensing optical signal is then split into two orthogonal polarization pulses by a polarization beam splitter. These two orthogonal polarization pulses enter the WDM-PM device together with other C-band polarization multiplexed optical signals to achieve multi-dimensional multiplexing of polarization and wavelength.

[0135] The multiplexed optical signal becomes two beams of multi-wavelength multiplexed light with orthogonal polarization states. The two beams of multi-wavelength multiplexed light each pass through a full-band wavelength division multiplexer again to achieve demultiplexing of C-band light and 1550nm spontaneous Raman scattered anti-Stokes light 1450nm wavelength light; then the two beams of multi-wavelength multiplexed light are coupled through a polarization beam splitter PBS to become a beam of WDM-PM light, which then enters the optical fiber for propagation;

[0136] The WDM-PM light carrying the signal propagates forward like the traditional optical communication system, and the sensing light signal returns to the transmitter due to backscattering Rayleigh and backscattering Raman, and enters the ROTDR and φOTDR data processing units for data processing after polarization diversity reception, thereby locating the continuity, loss, temperature, stress and vibration information of the optical fiber.

Claims

1. An integrated optical fiber communication and sensing architecture, characterized in that: include: Sensing system laser, coupler, polarization beam splitter, semiconductor optical amplifier, polarization multiplexing communication transmission system, polarization wavelength dual-dimensional demultiplexer based on full-row waveguide grating, namely WDM-PM device, coarse wavelength division multiplexer MMI-WDM, single-mode optical fiber, polarization multiplexing communication receiving system, polarization diversity dual-balanced photodetector PBPD, ROTDR and φOTDR data processing unit; Sensing system laser, coupler, polarization beam splitter, semiconductor optical amplifier, polarization multiplexing communication transmission system, polarization wavelength dual-dimensional demultiplexer based on full-row waveguide grating, namely WDM-PM device, coarse wavelength division multiplexer MMI-WDM, single-mode optical fiber, polarization multiplexing communication receiving system, polarization diversity dual-balanced photodetector PBPD, ROTDR and φOTDR data processing unit; At the transmitting end of the optical fiber communication system, the sensing light signal is emitted by the sensing system laser as a narrow linewidth laser, and then split by a coupler. A portion of the light is used as the local oscillator light to achieve coherent amplification of the backscattered Rayleigh light, and the remaining light is used as the signal light to be modulated by a semiconductor optical amplifier for single pulse. The modulated single pulse sensing optical signal is then split into two orthogonal polarization pulses by a polarization beam splitter. These two orthogonal polarization pulses enter the WDM-PM device together with other C-band polarization multiplexed optical signals to achieve multi-dimensional multiplexing of polarization and wavelength. The multiplexed optical signal becomes two beams of multi-wavelength multiplexed light with orthogonal polarization states. The two beams of multi-wavelength multiplexed light are respectively passed through a coarse wavelength division multiplexer MMI-WDM to demultiplex the C-band light and the 1550nm spontaneous Raman scattered anti-Stokes light 1450nm wavelength light. After that, the two beams of multi-wavelength multiplexed light are coupled into a beam of WDM-PM light through a polarization beam splitter, and then propagate in a single-mode optical fiber. The WDM-PM light carrying the signal propagates forward, and the sensing optical signal returns to the transmitter. After polarization diversity reception, it enters the sensing system for data processing, thereby locating the continuity, loss, temperature, stress and vibration information of the optical fiber.

2. The optical fiber communication sensing integrated architecture according to claim 1, characterized in that: The fiber optic communication sensing integrated architecture also includes a Raman amplifier, which uses the entire optical fiber as a gain medium to achieve gradual amplification of light in long-distance optical fibers.

3. The optical fiber communication sensing integrated architecture according to claim 1, characterized in that: The optical fiber communication system is a wavelength division multiplexing system in the C band.

4. The optical fiber communication sensing integrated architecture according to claim 1, characterized in that: The wavelength of the Raman pump laser is selected as the wavelength of the anti-Stokes light of the sensing optical signal.

5. The optical fiber communication sensing integrated architecture according to claim 1, characterized in that: The introduction of Raman amplifiers amplifies four types of light, including: The forward transmitted WDM-PM optical signal is the WDM-PM light that carries the signal; A single pulse of light for sensing in the forward direction; Backscattered Rayleigh light used in sensing to locate loss, continuity, stress, and vibration; Backscattered Rayleigh light used to locate on / off and temperature in sensing; After Raman amplification of the forward transmitted optical signal, it passes through the combination of polarization beam splitter and WDM-PM device to realize wavelength division multiplexing and polarization demultiplexing. The polarized light carrying different signals is received by the polarization multiplexing communication receiving system. The back-scattered Rayleigh light is returned along the original transmission fiber through Raman. During the return process, the back-scattered Rayleigh light is amplified by the Raman pump laser, and the back-scattered anti-Stokes light is superimposed with the Raman pump light to increase the basic optical power, making it easier for the detector to receive. After backscattering, the sensing optical signal containing the fiber connection, loss, stress, vibration, and temperature returns to the transmitting end and is firstly divided into two optical signals with orthogonal polarizations by a polarization beam splitter. The two optical signals with orthogonal polarizations are respectively passed through a coarse wavelength division multiplexer MMI-WDM to realize the demultiplexing of the C-band backscattered Rayleigh light and the anti-Stokes light of the backscattered Raman of the sensing light. After demultiplexing, the anti-Stokes light of Raman backscattering with orthogonal polarization states is received by polarization diversity and processed as ROTDR signal. By processing the light intensity information and comparing it with the pulse emission time, the temperature information of the entire optical fiber is demodulated and located. After demultiplexing, the back-Rayleigh scattered light of the C band with orthogonal polarization states is demultiplexed in wavelength and polarization state through the WDM-PM device. The back-Rayleigh scattered light with orthogonal polarization states of the single pulse light generated by the optical transmitter of the sensing system is coherent with the two polarization orthogonal local oscillator lights of the transmitting end after passing through the circulator and is received by the polarization diversity dual-balanced photodetector PBPD.

6. An integrated optical fiber communication and sensing architecture according to any one of claims 1 to 5, characterized in that: The polarization diversity dual balanced photodetector PBPD includes a polarization beam splitter PBS and a balanced photodetector BPD; the polarization beam splitter PBS divides the input local oscillator light and signal light into two orthogonal polarization states, and the two signal lights of different polarization states will be respectively coherent with the local oscillator light and received by two balanced photodetectors BPD, thereby realizing the coherent reception of two orthogonal polarization state signals; the signal detected by the PBPD is collected by the acquisition card and then processed, that is, the loss, continuity, stress, vibration and other information of the demodulated and located optical fiber is demodulated.

7. A working method of an integrated optical fiber communication and sensing architecture according to any one of claims 1 to 6, characterized in that: include: At the transmitting end of the optical fiber communication system, the sensing light signal is emitted by the sensing system laser as a narrow linewidth laser, and then modulated into a single pulse by a semiconductor optical amplifier; The modulated single pulse sensing optical signal is then split into two orthogonal polarization pulses by a polarization beam splitter. These two orthogonal polarization pulses enter the WDM-PM device together with other C-band polarization multiplexed optical signals to achieve multi-dimensional multiplexing of polarization and wavelength. The multiplexed optical signal becomes two beams of multi-wavelength multiplexed light with orthogonal polarization states. The two beams of multi-wavelength multiplexed light each pass through a full-band wavelength division multiplexer again to achieve demultiplexing of C-band light and 1550nm spontaneous Raman scattered anti-Stokes light 1450nm wavelength light; then the two beams of multi-wavelength multiplexed light are coupled through a polarization beam splitter PBS to become a beam of WDM-PM light, which then enters the optical fiber for propagation; The WDM-PM light carrying the signal propagates forward, and the sensing optical signal returns to the transmitting end, and enters the ROTDR and φOTDR data processing units for data processing after polarization diversity reception, thereby locating the continuity, loss, temperature, stress and vibration information of the optical fiber.

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